Pituitary Disorders Flashcards
Are are the clinical presentation of pituitary tumours
Visual loss, headache
What is prolactinoma
Where there is a prolactin secreting pituitary tumour
How is a prolactinoma treatmented
With dopamine as this decreases the size of the tumour
Radiotherapy or surgery of the pituitary gland affects its other functions
How big is a macro-adenoma
Over 1cm
What do prolactin inhibit
LH through GnRH
What are the symptoms of hyperprolactinaemia
Menstural disturbance
Fertility problems
Galactorrhoea - milky discharge from nipple
Vision loss due to the tumour
How does a tumour cause high prolactin below 5,000
It blocks dopamine release and TRH which both inhibit prolactin
What is likely to be the cause if prolactin is above 5,000
Active prolactin secretion (prolactinoma)
What are the different treatments for prolactinoma sand pituitary tumours
Prolactinomas need dopamine whereas pituitary tumours require surgery
what type of vision loss is accompanied by a pituitary tumour compressing the optic chiasm
bitemporal hemi-anopia
what symptoms are associated with a pituitary tumour growing sideways
pain and double vision as it compresses eye movement and pain nerves
if there is a tumour blocking movement of hormones from hypothalamus to anterior pituitary gland what will happen to the hormones produced by the anterior pituitary
they will decrease except prolactin which will increase as theres no negative control (hypopituitarism)
what does growth hormone deficiency result in
children = short statue adult = muscle weakness and tiredness
what is the result of a gonadotropin deficiency
children = delayed puberty adult = loss of secondary sexual characteristics
what are symptoms of a TSH deficiency
cold, weight gain, tiredness, slow pulse
what are the symptoms of an ACTH deficiency
tired, dizzy, low BP, low sodium
this is life threatening
adenomas of the pituitary gland most commonly produce which hormones
prolactin
GH
ACTH
which pituitary hormones can a basal blood test screen
TSH, LH, FSH, prolactin
which pituitary hormones require a dynamic blood test
cortisol and GH (these change throughout the day)
what types of dynamic blood tests can be taken
stimulation test for suspected deficiency and suppression tests for suspected excess
what stimulation and deficiency tests are used for ACTH and GH
ACTH
stimulation = response to hypoglycaemia
suppression = steroids
GH
stimulation = hypoglycaemic stress
suppression = glucose
how can the pituitary gland be viewed
by MRI
what is the treatment for prolactinoma
dopamine agonists to stimulate D2 receptors
what is the treatment for a non-functioning pituitary adenoma
surgery or radiotherapy
what drugs can cause high prolactin levels
dopamine antagonists e.g. anti-sickness and anti-psychotic drugs
what is acromegaly
where there is a GH secreting pituitary tumour
what are the long term complications of acromegaly
- premature cardiovascular death
- hypertension
- diabetes
- increased risk of thyroid cancer
- large hands and feet
what biochemical tests can confirm acromegaly
oral glucose tolerance test with failure to suppress GH
elevated IGF
how is acromegaly treated
- surgical removal of tumor
- dopamine agonists and somatostatins to decrease GH secretion
- radiotherapy
what is Cushing’s disease
where there is an ACTH secreting pituitary tumour
what is the appearance of Cushing’s disease
- round pink face
- skinny and weak arms and legs
- easily bruised
- red stretch marks on abdomen
- high blood pressure
- diabetes
- osteoporosis
what is the difference between Cushing’s disease and Cushing’s syndrome
cushing’s syndrome is high ACTH levels not due to a pituitary tumour
what is diabetes insipidus
conditions characterised by excesisve thirst and large quantities of pale urine due to a posterior pituitary gland secreting ADH
what is another name for ADH
vasopressin
what is the role of vasopressin
bind to a vasopressin receptor in the kidney opening aquaporins so that water is reabsorbed
what is the difference between cranial and nephrogenic diabetes insipidus
cranial = vasopressin deficiency nephrogenic = kidneys giving a lack of response to vasopressin
what are the consequences of diabetes insipidus
- severe dehydration
- high sodium levels (hypernatraemia)
- coma
- death
what is a pituitary apoplexy
a sudden vascular event in a pituitary tumour, this could be:
- bleeding in the tumour (haemorrhage)
- blood supply cut off (infarction)
what is the presentation of pituitary apoplexy
sudden onset headache
double vision
vision loss
hypopituitarism
in hypopituitarism which hormone deficiency is the most dangerous
ACTH/cortisol
